Method and apparatus for providing mobility within a network

ABSTRACT

The present invention is a novel method and apparatus for providing transparent mobility of an entity within a network. The present invention allows a given entity, which has a communication path set up between it and a peer entity, to move from one location to another, without informing the peer entity of this movement, and without having the communication path broken. The present invention is applicable to decentralized networks using the IP protocol, and is particularly applicable on networks wherein it is desired that the mobility mechanism neither introduces latency nor decreases the available bandwidth of the network. In the present invention, neither is latency increased nor is bandwidth utilization increased, as is done in other mobility models. Additionally, the present invention utilizes standard protocols that are widely available from a plurality of equipment manufacturers on a variety of platforms. Thus, the present invention provides a very cost-effective model for network providers that need to support transparent mobility within their network.

CROSS REFERENCE OF APPLICATION

This application claims priority from Provisional Application Serial No.60/163,325, filed Nov. 3, 1999, which is currently pending.

BACKGROUND OF THE INVENTION

I. Field of the Invention

The current invention relates to mobility within a telecommunicationssystem. More particularly, the present invention relates to a method andapparatus for transparently relocating an anchor point within theserving network of a wireless telecommunications system from onelocation to another.

II. Description of the Related Art

The use of a decentralized serving network for use in a wirelesstelecommunications system is disclosed in U.S. patent application. Ser.No. 09/158,047, entitled “DISTRIBUTED INFRASTRUCTURE FOR WIRELESS DATACOMMUNICATIONS”, applied for by the applicant of the present inventionnow U.S. Pat. No. 6,215,779, and incorporated by reference herein. Theabove application discusses a telecommunications decentralized servingnetwork in which, rather than there being a single point of control,there are multiple control points distributed throughout the servingnetwork of the telecommunications system.

The Internet Engineering Task Force (IETF) is the standards body thatcreates the majority of standards related to the Internet Protocol (IP).Many of the standards created by the IETF are called RFCs. RFC isshorthand for ‘Request For Comments.’

Open Shortest Path First (OSPF) was standardized by the IETF to address,in part, the routing of packets in a network in which one or more of therouters experiences a failure, thus enhancing the reliability of anetwork. OSPF was designed in such a way that, of all the routers whichare working at any given moment, the shortest path is taken from node Ato node B. Additionally, OSPF was designed such that, if multipleequivalent routes exist from node A to node B, any one of the equivalentroutes can be selected. With OSPF in place, a network with redundantroutes can perform load balancing on the routers. OSPF is available onmany makes and models of routers, and is described in IETF RFC 2328,incorporated by reference herein.

Mobile IP is present in many IETF standards to make it possible for adevice, containing an IP address, to travel through a network (ornetworks). The standard, RFC 2002, ‘IP Mobility Support,’ incorporatedby reference herein, addresses the problem of IP Mobility, and uses asolution termed ‘Mobile IP.’ Several other Mobile IP related standardsalso exist, such as RFCs 2006, 2041, 2290, 2344, and 2356, each of whichis incorporated by reference herein. Local Area Network (LAN) systemadministrators that want to support mobility are guided by the IETFstandards to use Mobile IP. Mobile IP provides support not only formobility within a LAN, but also for mobility within a Wide Area Network(WAN).

In a decentralized telecommunications network, the service deviceschosen are widely available off-the-shelf units that use open standardsfor their interfaces rather than proprietary protocols that are limitedto a single supplier. Many, if not all, of the service devices aredesigned to communicate with a single anchor point for each activesession. Meaning, such off-the-shelf devices, and the protocols theyincorporate, are not designed to begin a session with one device andends the same session with a different device. This restriction can leadto non-optimized routing for individual sessions. Such non-optimizedrouting situations are illustrated in FIG. 8A and FIG. 8B. What isneeded is a method by which a service device's anchor point for anactive session can be relocated without the need for specific anchorpoint relocation support in the service device. Specifically, such amethod should be very efficient and robust, minimizing latency andbandwidth usage.

SUMMARY OF THE INVENTION

The present invention is a novel method and apparatus for providingtransparent mobility of an entity within a serving network of a wirelesstelecommunications system. The invention provides for the transparentmobility of a data anchor point within a network, allowing the anchorpoint to move from one physical location of the network to anotherphysical location of the network. The type of mobility is termed‘transparent’ because the peer entity communicating with the anchorpoint doesn't receive a message indicating that the anchor point hasmoved, nor is the peer entity required to perform any special functionsto remain in communication with an anchor point that has moved from onelocation to another. In other words, the peer entity communicating withthe data anchor point performs no differently in a session in which theanchor point remains fixed than it does in a session in which the anchorpoint changes physical locations.

The present invention is applicable to decentralized networks in whichtransparent mobility is desired. The present invention is particularlyapplicable on networks wherein it is desired that the mobility mechanismneither introduces latency nor decreases the available bandwidth of thenetwork. Such networks include, but are not limited to, a CDMA wirelessdata network and a GSM wireless data network.

All embodiments of the present invention are novel methods and apparatusfor handling mobility within a serving network of a wirelesstelecommunications system. The exemplary embodiment of the presentinvention has broader applicability, in that it provides a novel methodfor handling mobility in all types of networks, including corporate andgovernment networks. Other mobility models can require a centralizednetwork to manage anchor point mobility. Additionally, other mobilitymodels can use of a significant amount of available bandwidth and cansignificantly increase latency. The present invention neither hasdeleterious latency nor bandwidth effects. Additionally, the presentinvention utilizes standard protocols that are widely available from aplurality of equipment manufacturers on a variety of platforms. Thus,the present invention provides a very cost-effective model for networkproviders that desire to support transparent mobility within theirnetwork.

The exemplary embodiment of the present invention uses OSPF to achievetransparent anchor point mobility. Mobile IP is used in an alternativeembodiment of the present invention to provide transparent anchor pointmobility in the serving network of a wireless telecommunications system.OSPF is used in the exemplary embodiment of the present inventionbecause the use of OSPF does not introduce the tunneling overhead thatis introduced Mobile IP, and OSPF does not introduce the latency thatcan be caused by the indirect routing common in Mobile IP.

BRIEF DESCRIPTION OF THE DRAWINGS

The features, objects, and advantages of the present invention willbecome more apparent from the detailed description set forth below whentaken in conjunction with the drawings in which like referencecharacters identify correspondingly throughout and wherein:

FIG. 1 is a block diagram of exemplary embodiment of an Access Terminalin communications with a Wireless Telecommunications DecentralizedServing Network.;

FIG. 2 is a functional block diagram of an exemplary embodiment of adecentralized serving network of a wireless telecommunications system;

FIG. 3 is a functional block diagram of an exemplary embodiment of anaccess point;

FIG. 4 is a functional block diagram of an exemplary embodiment of amodem pool controller;

FIG. 5 is a functional block diagram of an exemplary embodiment of amodem pool transceiver;

FIG. 6A is a network diagram of an exemplary embodiment of the data pathfrom an access terminal to the internet, wherein the access terminal isin communication with a first modem pool transceiver of a servingnetwork of a wireless telecommunications system;

FIG. 6B is a block diagram of the data path taken in relation to FIG.6A;

FIG. 7A is a network diagram of an exemplary embodiment of the data pathfrom an access terminal to the internet, wherein the access terminal isin soft-handoff with a first and second modem pool transceiver of aserving network of a wireless telecommunications system;

FIG. 7B is a block diagram of the data path taken in relation to FIG.7A;

FIG. 8A is a network diagram of an exemplary embodiment of the data pathfrom an access terminal to the internet, wherein the access terminal isin communication with a second modem pool transceiver of a servingnetwork of a wireless telecommunications system, and the anchor pointtransfer of the present invention has yet to occur;

FIG. 8B is a block diagram of the data path taken in relation to FIG.8A;

FIGS. 9A-9B are a flowchart illustrating an exemplary embodiment of theanchor point transfer methodology of the present invention.

FIG. 10A is a network diagram of an exemplary embodiment of the datapath from an access terminal to the internet, wherein the accessterminal is in communication with a second modem pool transceiver of aserving network of a wireless telecommunications system, and the anchorpoint transfer methodology of the present invention has been utilized;

FIG. 10B is a block diagram of the data path taken in relation to FIG.10A; and

FIG. 11 is a functional block diagram of a preferred embodiment of adecentralized serving network of a wireless telecommunications system.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

FIG. 1 is a block diagram of exemplary embodiment of an Access Terminalin communications with a Wireless Telecommunications DecentralizedServing Network. Access terminal 110 is a wireless terminal that can beused to access one or more of a plurality of services, including PublicSwitched Telephone Network (PSTN) and Internet services, offered by theserving network of a wireless telecommunications system 120. Wirelesstelecommunications system 120, and PSTN 122 and Internet 124 to whichwireless telecommunications system 120 connects, are further describedin reference to FIG. 2. In the exemplary embodiment, access terminal 110is able to connect to the serving network of a wirelesstelecommunications system via the use of a radio antenna. Accessterminal 110 can maintain a communication link with the serving networkof a wireless telecommunications system by communicating with one ormore access points, further described in reference to FIG. 2 and FIG. 3.

FIG. 2 is a functional block diagram of an exemplary embodiment of adecentralized serving network of a wireless telecommunications system,hereinafter also referred to as network 120. Access terminal 110 cancommunicate with network 120 over a wireless link.

Network 120 is comprised of a plurality of access points 220, which cancommunicate with access points 110, and are further described inreference to FIG. 3. Additionally, network 120 is further comprised ofone or more router(s) 260, which connect access points 220 to servicedevices 270. Service Devices 270 are connected to PSIN 122 and Internet124. Although network 120 connects to external entities PSTN 122 andInternet 124 in FIG. 2, the invention is not limited to a network whichconnects to these entities. One skilled in the art would know that otherentities, such as a private external information provider, or a billingservice entity, could be connected to network 120 as well. Additionally,it is not required that either PSTN 122 or Internet 124 be connected tonetwork 120. PSTN 122 and Internet 124 were put in FIG. 2, to give anillustration of the type of entities to which network 120 could beconnected.

PSTN 122 represents the Public Switched Telephone Network, the aggregateof all of the circuit switched voice networks throughout the world. Theterm PSTN is well known to those experienced in the field oftelecommunications.

Internet 124 represents the public Internet, a network of computers thatspans the world and is used by individuals, governments, corporations,and organizations to share information amongst computers and computingdevices. The term Internet is well know to those experience in the fieldof telecommunications.

H323 Gateway 271 provides H.323 services in accordance with the H.323standard, thus providing standardized multimedia communications over anetwork. The H.323 standard was developed by the InternationalTelecommunications Union, and is described in ITU-T RecommendationH.323. H.323 Gateway is connected to PSTN 122 and Internet 124. Oneskilled in the art of the related fields would be familiar with theservices provided by an H323 Gateway.

NAS 272 is a Network Access Server. NAS 272 provides packet dataservices in accordance with the IETF Internet Draft “Network AccessServer Requirements Next Generation (NASREQNG) NAS Model.” One skilledin the art of the related fields would be familiar with the servicesprovided by a Network Access Server.

AAA Server 274 provides Authentication, Authorization, and Accountingservices. A RADIUS server is one example of an AAA server, and isdescribed in IETF RFC 2138. One skilled in the art of the related fieldswould be familiar with the services provided by an AAA server.

DHCP Server 276 provides dynamic host configuration services inaccordance with the Dynamic Host Configuration Protocol, which isdescribed in IETF RFC 2131. One skilled in the art of the related fieldswould be familiar with the services provided by a DHCP server.

DNS Server 278 provides Domain Name Services. DNS is described in“Internetworking with TCP/IP Volume I, Principles, Protocols, andArchitecture,” by Douglas E. Comer. One skilled in the art of therelated fields would be familiar with the services provided by a DNSserver.

All of the above devices are “off-the-shelf” and use standard,nonproprietary protocols.

Although the illustration of Service Devices 270 contains H323 Gateway271, NAS 272, AAA Server 274, DHCP Server 276, and DNS Server 278, theinvention is not limited to a network which contains exactly theseservice devices. One skilled in the art would know that other services,such as a Web page server, could be one of the service devices inService Devices 270. Additionally, it is not required that any or all ofthe service devices illustrated in Service Devices 270 be present. Thesechosen devices were illustrated to given an example of the type ofentities that could be contained in Service Devices 270.

Network 120 connects Access Points 220 and Service Devices 270 togethervia various Ethernet connections and the use of a router 260. Router 260is an off-the-shelf router which routes (forwards) packets received fromone physical interface to one or more other interfaces using an internalprocess to determine to which interface to forward each received packet.Routers are well known to those skilled in the art, and are oftenreferred to by other names, such as gateways or switches. In theexemplary embodiment of the invention, router 260 is an off-the-shelfrouter which forwards IP (Internet Protocol) packets received from aplurality of Ethernet transports 280 to one or more of said Ethernettransports 280. In the exemplary embodiment, router 260 supports theOSPF routing protocol. Ethernet is defined in IEEE 802.3, a standardpublished by the Institute of Electrical and Electronic Engineers(IEEE). The OSPF routing protocol is described in IETF RFC 2328. TheOSPF routing protocol allows standard messages to be sent betweenrouters to update their routing tables, such that IP packets can bedelivered via the data path that has the lowest cost (the term ‘cost’ isdescribed in IETF RFC 2328). The OSPF protocol has an age field that istransmitted in each Link State Advertisement message. The age fieldindicates to a receiving router how long the Link State Advertisementshould remain valid for. A receiving router associates an age with theLink State Advertisement consistent with the age field received in aLink State Advertisement. A receiving router increments the associatedages for its routes as time passes. A receiving router compares theseages with the maximum age. Once an age associated with a route reachesthe maximum age, the route is deleted. Hereinafter, the maximum age isreferred to as MaxAge, as is per the description in IETF RFC 2328. Oneskilled in the art of data networks would be familiar with Ethernet, IP,and OSPF.

Although the illustration of network 120 connects access points 220,router 260, and Service Devices 270, via an IP over Ethernet transport280, the invention is not limited to a network with a sole transportmechanism consisting of IP over Ethernet. One skilled in the art ofnetworking is familiar with an ethernet transport 280 that is used tocarry IP packets from one point on a network to another. One skilled inthe art would know that other transports, such as Asynchronous TransferMode (ATM), could be used as a transport over all or a portion ofnetwork 120, in an alternative embodiment. Although, in the exemplaryembodiment, network 120 consists of two subnets divided by a singlerouter 260, an alternative embodiment could consist of two or morerouters 260, connecting two or more subnets.

FIG. 3 is a functional block diagram of an exemplary embodiment of anAccess Point. Access Point 220 is the portion of network 120 thatreceives data from a service device 270 and creates capsules andtransmits them over a wireless link to an access terminal 110.

Access point 220 consists of a single MPC 320, further described inreference to FIG. 4, and zero or more MPTs 330 connected each of whichis connected to an antenna, further described in reference to FIG. 5. Inthe exemplary embodiment, MPC 320 and MPTs 330 are connected to router350 via IP over Ethernet transport 340.

Although the illustration of Access Point 220 connects MPC 320 and MPTs330 via an IP over Ethernet transport 340, the invention is not limitedto such a transport. In one alternative embodiment, an ATM transport isused. In another alternative embodiment, MPC 320, MPTs 330, and router350 are located on a single processing unit, and the router receivespackets from these logical memory units via memory functions andsignaling internal to the processor. One skilled in the art would knowthat several other transports are available as well.

FIG. 4 is a functional block diagram of an exemplary embodiment of aModem Pool Controller (MPC) 320. MPC 320 is analogous to a Base StationController plus a Visitor Location Register (VLR), known to thoseskilled in the art of wireless telecommunication. Whereas a Base StationController controls certain functions in a centralized serving networkof a wireless telecommunications system, MPC 320 performs many of thosesame functions in the exemplary decentralized network. For example, MPC320 handles connection control for access terminals 110, and alsohandles the implementation of the Radio Link Protocol (RLP). An RLPprovides a means for transporting a data stream between a remote stationand wireless telecommunications system. As is known to one skilled inthe art, an RLP used for the TIA/EIA/IS-95B is described in Radio LinkProtocol (RLP) is described in TIA/EIA/IS-707-A.8, entitled “DATASERVICE OPTIONS FOR SPREAD SPECTRUM SYSTEMS: RADIO LINK PROTOCOL TYPE2”, incorporated by reference herein. MPC 320 also handles a pluralityof processes unique to the decentralized network and the presentinvention, especially in regards to the present invention. The processof the present invention will be described in great detail in relationto FIGS. 9A-9B.

For each active Internet data connection associated with a given MPC320, MPC 320 generates capsules to be transmitted by one or more MPTs330, and ships these capsules to MPT 330. Likewise, when MPC 320receives a capsule from one or MPTs 330, it unencapsulates the payloadof the capsule and processes the data. MPC 320 contains one CommonController (CC) 420 and zero or more dedicated controllers (DCs) 430.Each dedicated controller 430 functions as an anchor point to theservice device(s) 270 to which it is connected.

Exactly one CC 420 exists for each instance of MPC 320. As illustratedin FIG. 4, CC 420 is assigned two unique IP addresses, IP_(CCT) andIP_(CCO). One of these IP addresses, IP_(CCT), is used whencommunicating with MPTs 330. The other IP address, IP_(CCO), is usedwhen communicating with entities present in network 120 other than MPTs330.

Each time a session between an access terminal 110 and a network 120starts, CC 420 dynamically allocates resources for a DC 430. Each DC 430handles the generation of and the reception of capsules associated withthe access terminal with which it is associated. Each time a sessionbetween an access terminal 110 and a network 120 ends, CC 420 deletesthe instance of DC 430. Whenever an instance of DC 430 is deleted, theresources previously allocated to that instance are deallocated. Asillustrated, a plurality of zero or more DCs 430 can coexist within MPC320 at any given time.

Each time CC 420 allocates resources for an instance of DC 430, theinstance of DC 430 is assigned two unique IP addresses, IP_(DCT) andIP_(DCO). One of these IP addresses, IP_(DCT), is used whencommunicating with MPTs 330. The other IP address, IP_(DCO), is usedwhen communicating with entities present in network 120 other than MPTs330, such as NAS 272. In blocks 430A, 430B, and 430N, the characters‘A’, ‘B’, and ‘N’, respectively, have been added to the subscripts ofeach of the IP addresses. This was done to illustrate that, in theexemplary embodiment, at any given point in time in which multipleinstances of DC 430 exist within MPC 320, each such instance has its ownunique pair of IP addresses.

CC 420 and DCs 430 send and receive messages over IP transport 440 toInternal Router 450. In the exemplary embodiment, IP transport 440 is amemory bus over which IP packets can travel from one process to anotherand to an interface card. Internal Router 450 is a network interfacecard, which routes IP packets to/from IP transport 440 and externaltransport 340. The invention is not limited to this embodiment. As oneskilled in the art would know, there are other embodiments, such asEthernet, which could be used to transport IP packets within MPC 320 andexternal transport 340.

FIG. 5 is a functional block diagram of an exemplary embodiment of aModem Pool Transceiver (MPT) 330. MPT 330 handles the transmitting andreceiving of capsules to/from access terminal 110. In the exemplaryembodiment, communications between MPT 330 and access terminal 110utilize variable rate spread spectrum techniques as described in U.S.Pat. application Ser. No. 08/963,386 entitled “Method and Apparatus forHigh Rate Packet Data Transmission” filed on Nov. 3, 1997, assigned tothe assignee of the present invention and incorporated by referenceherein. MPT 330 contains one common transceiver (CT) 520 and a pluralityof zero or more dedicated transceivers (DTs) 530, each of which iscapable of performing the spread spectrum modulation and demodulationused for communications with one or more access terminals.

In the exemplary embodiment, exactly one CT 520 exists for each instanceof MPT 330. As illustrated in FIG. 5, CT 520 is assigned one unique IPaddresses, IP_(CT), to communicate with entities present in network 120.

Each time it is desired open a dedicated communication link between anaccess terminal 110 and an MPT 330, CT 520 dynamically creates aninstance of DT 530. Each DT 530 handles the transmission/reception ofcapsules associated with the dedicated communication link to an accessterminal 110. Each time it is desired to close a dedicated communicationlink between an access terminal 110 and an MPT 330, CT 520 deletes theinstance of DT 530. As illustrated in FIG. 5, a plurality of zero ormore DTs 530 can coexist within MPT 330 at any given time.

Each instance of DT 530 is assigned its own unique IP address IP_(DT)used to communicate with entities present in network 120. In blocks530A, 530B, and 530N, the characters ‘A’, ‘B’, and ‘N’, respectively,have been added to the subscripts of each of the IP addresses. This wasdone to illustrate that, in the exemplary embodiment, at any given pointin time in which multiple instances of DT 530 exist within MPT 330, eachsuch instance has its own unique IP addresses. In other words, the IPaddresses assigned to each concurrent instance of MPT 330 are not thesame.

CT 520 and DTs 530 send and receive messages over IP transport 540 toInternal Router 550. In the exemplary embodiment, IP transport 540 is amemory bus over which IP packets can travel from one process to anotherand to an interface card. Internal Router 550 is a network interfacecard, which routes IP packets to/from IP transport 540 and Ethernet 340.The invention is not limited to this embodiment. As one skilled in theart would know, there are other embodiments, such as ATM, which could beused to transport IP packets within MPT 330 and external transport 340.

Additionally, transceivers CT 520 and DT 530 have the ability totransmit and receive data to access terminals via the use of one commonantenna, as illustrated. In an alternative embodiment, transceivers CT520 and DT 530 have the ability to transmit and/or receive data via theuse of a plurality of two or more antennas.

FIG. 6A is a network diagram that illustrates the entities that are usedin an Internet data connection when an access terminal 110 has awireless data communication channel open with a single access point 220.In FIG. 6A, the following labels are applied.

In the exemplary Internet data connection, access terminal 110 transmitsand receives IP packets embedded within PPP packets by embedding the PPPpackets, or portions thereof, into wireless packets that adhere to thewireless protocol.

The entities diagramed within access point 220A are only those entitiesthat are part of the data path for the Internet data connection. Forinstance, although only a single MPT, MPT 330AA, is diagramed, there maybe other MPTs 330 within access point 220 that are not part of theInternet data connection in question. DC 430AA has an IP address ofIP_(DCOAA) associated with it for use in communicating with NAS 272, andDC 430AA has an IP address of IP_(DCTAA) for use in communicating withone or more instances of MPT 330. MPT 330AA is an instance of MPT 330,earlier described in reference to FIG. 3 and FIG. 5.

Wireless protocol packets are transmitted between MPT 330AA and accessterminal 110 over wireless transport 610.

FIG. 6B is a diagram showing the exemplary data flow for the Internetdata connection adhering to the data path illustrated in FIG. 6A. On theforward link, an IP packet having a destination IP address associatedwith access terminal 110 travels from Internet 124 over ethernettransport 280E to NAS 272. In NAS 272, the packet is encapsulated in aPPP packet, which is further encapsulated into an L2TP packet with adestination IP address associated with DC 430AA (IP_(DCOAA)) locatedwithin MPC 320A. L2TP is well known to those skilled in the art ofnetworking, and is described in IETF RFC 2661. This L2TP packet istransmitted over ethernet transport 280D to router 260. Router 260forwards this L2TP packet over Ethernet transport 280C to router 350A.Router 350A then forwards this L2TP packet over Ethernet transport 340Ato its destination of DC 430AA. DC 430AA, located in MPC 320A, receivesthe L2TP packet and unencapsulates the embedded PPP frame. DC 430AA,then, encapsulates the PPP frame into one or more wireless protocolcapsules, which are further encapsulated into IP packets with adestination address associated with MPT 330AA. These IP packets are thentransmitted over ethernet link 340A to MPT 330AA. MPT 330AAunencapsulates the wireless protocol capsules from the IP packets andtransmits these capsules to access terminal 110 over wireless transport610.

As is easily understood by one skilled in the art, the opposite path istaken for packets traveling in the direction of the reverse link. It isalso easily understood by one skilled in the art that various link layerprotocols exist that could be used in lieu of PPP and L2TP.

FIG. 7A is a network diagram that illustrates the entities that are usedin an Internet data connection when access terminal 110 has a wirelessdata communication channel open with two access points 220. Inparticular, FIG. 7A illustrates the network entities that would be inuse if access terminal 110 was previously connected as diagramed in FIG.6A, and subsequently access terminal 110 went into a soft-handoff withaccess point 220B. In FIG. 7A, all labels have the same meaning as theydid in reference to FIG. 6A, with the one following exception.

Access point 220B was not present in FIG. 6A. The entities diagramedwithin access point 220B are only those entities that are part of thedata path for the aforementioned Internet data connection. Wirelessprotocol packets are transmitted between MPT 330BA and access terminal110 over transport 610. Although, MPT 330BA is different from MPT 330AA,since access terminal 110 receives an aggregate signal from these MPTs330, it is considered a single transport 610.

FIG. 7B is a diagram showing the exemplary data flow for the Internetdata connection adhering to the data path illustrated in FIG. 7A. On theforward link, an IP packet having a destination IP address associatedwith access terminal 110 travels from Internet 124 over ethernettransport 280E to NAS 272. In NAS 272, the packet is encapsulated in aPPP packet, which is further encapsulated into an L2TP packet with adestination IP address DC 430AA (IP_(DCOAA)), located within MPC 320A.This L2TP packet is transmitted over ethernet transport 280D to router260. Router 260 forwards this L2TP packet over Ethernet transport 280Cto router 350A. Router 350A then forwards this L2TP packet over Ethernettransport 340A to its destination of DC 430AA. DC 430AA, located in MPC320A, receives the L2TP packet and unencapsulates the embedded PPPframe. DC 430AA, then, encapsulates the PPP frame into one or morewireless protocol capsules, which are further encapsulated into IPpackets having a destination address(es) associated with MPT 330AA andMPT 330BA.

The packets destined for the IP address associated with MPT 330AA arereceived by MPT 330AA via ethernet transport 340A. MPT 330AAunencapsulates the wireless protocol capsules from the IP packets andtransmits the wireless protocol capsules to access terminal 110 overwireless transport 610 at the times designated in the IP packets.

The packets destined for the IP address associated with MPT 330BA arereceived by router 350A via Ethernet transport 340A. Router 350Aforwards these IP packets over Ethernet transport 280C to router 350B.Router 350B forwards these IP packets over Ethernet transport 340B toits destination of MPT 330BA. MPT 330BA unencapsulates the wirelessprotocol capsules from the IP packets, and transmits the wirelessprotocol capsules to access terminal 110 over wireless transport 610 atthe time designated in the IP packets.

In one embodiment, the timestamps in the IP packets are such that thesame internet payload is transmitted both from MPT 330AA and MPT 330BAover link 610 at the same time.

As is easily understood by one skilled in the art, the opposite path istaken for packets traveling in the direction of the reverse link.

FIG. 8A is a network diagram that illustrates, with one exception (MPC320B), the entities that are used for forward and reverse link data flowin an Internet data connection when access terminal 110 has a wirelessdata communication channel open with a single access point 220B, but inwhich the capsules received by access point 220B are transmitted to anMPC 320A within another access point 220A. In particular, FIG. 8Aillustrates the network entities that would be in use if access terminal110 was previously connected as diagramed in FIG. 7A, and subsequentlythe link between access terminal 110 and access point 220A wasterminated. In other words, FIG. 8A can represent the entitiesassociated with a given Internet data connection, just after accessterminal 110 completes a soft hand-off. Alternatively, FIG. 8Aillustrates the network entities that would be in use if access terminal110 was previously connected as diagramed in FIG. 7A, and subsequently ahard-handoff to MPT 330B within access point 220B was performed. In FIG.8A, all labels have the same meaning as they did in reference to FIG.7A.

There is one entity diagramed in FIG. 8A, MPC 320B, the exceptionmentioned above, which is not used for the forward and reverse link dataflow of said Internet data connection. This entity, MPC 320B, is aninstance of MPC 320, earlier described in reference to FIG. 3 and FIG.4. The use of MPC 320B will be further described in reference to FIGS. 9and 10.

FIG. 8B is a diagram showing the exemplary data flow for the Internetdata connection adhering to the data path illustrated in FIG. 8A. On theforward link, an IP packet having a destination IP address associatedwith access terminal 110 is travels from Internet 124 over ethernettransport 280E to NAS 272. In NAS 272, the packet is encapsulated in aPPP packet, which is further encapsulated into an L2TP packet with adestination IP address associated with DC 430AA (IP_(DCOAA)), locatedwithin MPC 320A. This L2TP packet is transmitted over ethernet transport280D to router 260. Router 260 forwards this L2TP packet over Ethernettransport 280C to router 350A. Router 350A then forwards this L2TPpacket over Ethernet transport 340A to its destination of DC 430AA. DC430AA, located in MPC 320A, receives the L2TP packet and unencapsulatesthe embedded PPP frame. DC 430AA, then, encapsulates the PPP frame intoone or more wireless protocol capsules, which are further encapsulatedinto IP packets with a destination address associated with MPT 330BA.

The packets destined for the IP address associated with MPT 330BA arereceived by router 350A via Ethernet transport 340A. Router 350Aforwards these IP packets over Ethernet transport 280C to router 350B.Router 350B forwards these IP packets over Ethernet transport 340B toits destination of MPT 330BA. MPT 330BA unencapsulates the wirelessprotocol capsules from the IP packets, and transmits the wirelessprotocol capsules to access terminal 110 over wireless transport 610.

As is easily understood by one skilled in the art, the opposite path istaken for packets traveling in the direction of the reverse link.

FIGS. 9A-9B are a flowchart illustrating an exemplary embodiment of theanchor point transfer methodology of the present invention. Themethodology presents a means by which an entity that exists in onelocation in a network can be moved to another location in the network,and wherein such methodology results in a very efficient use of thebandwidth of the network.

It is worth noting that at the time at which block 1000 is reached, MPC320A has the ability to route packets to IP_(DCOAA) at a nominally highcost. This cost, although nominally high, is the lowest cost routeassociated with the delivery of packets in network 120 to IP addressIP_(DCOAA).

In block 1000, a first MPC 320 makes the decision that one of its DCs430 should be moved to a second MPC 320 within the network. In theexemplary embodiment of the present invention, such a decision would bemade when in a Internet data connection, the DC 430 resources of oneaccess point 220 are utilized, but wherein said DC 430 does notcommunicate with any MPT 330 within the same access point 220. FIGS. 8Aand 8B provide illustrations of an exemplary embodiment of a network atan instant in which it is desirable to implement the methodology of thepresent invention. FIGS. 10A and 10B provide illustrations of anexemplary embodiment of a network at an instant immediately followingthe utilization of the methodology of the present invention.

For the sake of clarity and simplicity, FIGS. 9A-9B are hereafterdescribed with specific reference to the entities referenced in FIGS.8A, 8B, 10A, and 10B, whenever possible. However, one skilled in the artwill appreciate that the invention herein is not limited to the specificentities or network configurations of those figures. Referencing FIG.8A, in block 1000, MPC 320A makes the decision to move DC 430AA from MPC320A to MPC 320B. The process then moves to block 1010.

In block 1010, MPC 320A sends a message to MPC 320B. The messagecontains a request for MPC 320B to begin setting up a DC 430 thatcontains network interface related information, such as NAScommunication information, equivalent to that in DC 430AA. In theexemplary embodiment, the message contains the L2TP tunnel stateinformation associated with DC 430AA, such as its IP address, IP_(DCOAA)and the Tunnel ID of its L2TP session. The process then moves to block1020.

In block 1020, MPC 320B receives the message referenced in block 1010.In accordance with the message request, MPC 320B allocates resources fora new DC 430. The new DC 430 is initialized to the L2TP tunnel valuesreceived in the aforementioned message. Although this new DC 430,present in MPC 320B has been created and initialized, it is not used ina Internet data connection at this point. The process then moves toblock 1030.

In block 1030, MPC 320B sends a message to its local router, router350B, stating that MPC 320B has the ability to route packets toIP_(DCOAA) at a nominally low cost. In the exemplary embodiment, thismessage is an OSPF link state advertisement (LSA). In one embodiment,the message sent is an IP broadcast or multicast message, thus allowinga plurality of local routers to receive the message. The routing costadvertised in this message, being nominally low, is lower than thenominally high cost route that is currently associated with MPC 320A. Asall of the routers in network 120 are OSPF capable, this new low costroute, for packets having a destination address of IP_(DCOAA), willpropagate throughout the routers of network 120. Thus, at some point inthe future, after the propagation of the routing information takesplace, routers will begin to route packets having a destination addressof IP_(DCOAA) to MPC 320B. The process then moves to block 1040.

In block 1040, MPC 320B sets a first timer. The timer is set to a valuerepresentative of the maximum amount of time it should take for the lowcost route, mentioned in reference to block 1030, to propagatethroughout network 120. The process then moves to block 1060.

The methodology of the present invention is such that the process doesnot move to block 1070 until it can be assured that the propagation ofthe low cost route throughout network 120 has taken place. The step thatis represented by block 1060 is that in which that assurance is gained.In block 1060, MPC 320B checks whether said first timer has expired orwhether it has received a packet destined for IP_(DCOAA). If neitherevent has occurred, the process returns to block 1060, where the samecheck is again performed. In block 1060, if either said first timer hasexpired, or MPC 320B has received a packet destined for IP_(DCOAA), thenthe process moves to block 1070.

In block 1070, MPC 320B sends a message to MPC 320A. The messagecontains a request that MPC 320A complete the transfer of DC 430AA toMPC 320B.

In block 1080, MPC 320A receives the aforementioned message. Inresponse, MPC 320A sends a message to its local router, stating thatpackets with an IP destination address of IP_(DCOAA) and packets with anIP destination address of IP_(DCTAA) should no longer be routed to MPC320A. In the exemplary embodiment, this message is an OSPF LSA. In oneembodiment, the message sent is an IP broadcast message, thus allowing aplurality of local routers to receive the message. As all of the routersin network 120 are OSPF capable, the fact that MPC 320A is no longerfunctioning as a router for packets having destination addressesassociated with DC 430AA will propagate throughout the routers ofnetwork 120. Thus, at some point in the future, after the propagation ofthe routing information takes place, routers will no longer associateMPC 320A as a router that can be used when trying to route packets to DC430AA. The process then moves to block 1090.

In block 1090, MPC 320A sends a message to MPC 320B. The messagecontains transceiver (e.g., MPT) communication information, such asIP_(DCTAA) and the IP address of MPT 330BA. Additional informationuseful to the transfer of DC 430AA from MPC 320A to MPC 320B may also beincluded. In one embodiment, RLP state information is contained in themessage. In another embodiment, the wireless protocol's Layer 2 stateinformation is contained in the message. The process then moves to block1100. Layer 2 is a layer of the telecommunications system that providesfor the correct transmission and reception of signaling messages,including partial duplicate detection. This is known to one skilled inthe art, and is described in Telecommunications Industry AssociationTIA/EIA/IS-95-B, entitled “MOBILE STATION-BASE STATION COMPATIBILITYSTANDARD FOR DUAL-MODE WIDEBAND SPREAD SPECTRUM CELLULAR SYSTEMS”,incorporated by reference herein, and hereinafter referred to as IS-95-B

In block 1100, MPC 320A deallocates all of its resources associated withDC 430AA. The process then moves to block 1110.

In block 1110, MPC 320B receives the message that had been transmittedby MPC 320A, described in reference to block 1090. In accordance withthe receipt of this message, MPC 320B completes the initialization ofthe new DC (the one referenced in the description of block 1020) byinitializing said new DC to the values received in this message. At thispoint, said new DC in MPC 320B is configured essentially the same as wasDC 430AA in MPC 320A, prior to its deallocation specified in block 1100.Thus, although the new DC in MPC 320B is physically housed in adifferent location than was DC 430AA, which was housed in MPC 320A, thetwo DCs are in essence one and the same. Thus, at this point,considering that DC 430AA was deallocated in block 1100, and consideringthat the new DC is essentially the same as the deallocated one, the newDC in MPC 320B is hereinafter termed DC 430AA, and is illustrated assuch in FIG. 10A. The process then moves to block 1120.

In block 11120, MPC 320B sends a message to its local router, router350B, stating that MPC 320B has the ability to route packets toIP_(DCTAA) at a nominally low cost (a cost lower than the costpreviously associated with the routing of this address to MPC 320A). Inthe exemplary embodiment, this message is an OSPF link stateadvertisement. As all of the routers in network 120 are OSPF capable,this new low cost route, for packets having a destination address ofIP_(DCTAA), will propagate throughout the routers of network 120. Thus,at some point in the future, after the propagation of the routinginformation takes place, routers will begin to route packets having adestination address of IP_(DCTAA) to MPC 320B. Due to the fact that allsuch packets originate from MPT 330BA, and the fact that MPT 330BA is onthe same subnet as MPC 320B, in all likelihood this operation will beextremely fast. Gratuitous ARP, a term known those skilled in the art ofnetworking, refers to the generation of an unsolicited ARP. In oneembodiment, MPC 320B sends a gratuitous ARP message to all other membersof its subnet, informing those entities that all packets with atdestination address of IP_(DCTAA) should be sent to the ethernethardware address of MPC 320B. Although not necessary, the use of thegratuitous ARP by itself, or in conjunction with an OSPF message, candecrease the amount of time it takes for packets from MPT 330BA to berouted to MPC 320B. The process then moves to block 1130.

In block 1130, MPC 320B sets a second timer. The timer is set to a valuerepresentative of the maximum amount of time it should take for the lowcost route, mentioned in reference to block 1120, to propagatethroughout network 120. In the exemplary embodiment, this second timeris set to the same value that the first timer was set to in block 1040.The process then moves to block 1140.

The methodology of the present invention is such that the process doesnot move to block 1150 until it can be assured that the aforementionedpropagation of the low cost route throughout network 120 has takenplace. The step that is represented by block 1140 is that in which thatassurance is gained. In block 1140, MPC 320B checks whether the secondtimer has expired or whether it has received a packet destined forIP_(DCTAA). If neither event has occurred, the process returns to block1140, where the same check is again performed. In block 1140, if eitherthe second timer has expired, or MPC 320B has received a packet destinedfor IP_(DCTAA), then the process moves to block 1150.

In block 1150, MPC 320B sends zero or more messages to access terminal110 over transport 610. In the exemplary embodiment, the newlyinitialized DC 430AA contains neither the RLP state nor the wirelessLayer 2 state that was present in DC 430AA when it resided in MPC 320A.Thus, in the exemplary embodiment, DC 430AA transmits messages to accessterminal 110, requesting that access terminal 110 reset its RLP andwireless Layer 2 layers. In an alternative embodiment, DC 430AA containsall the state information that was contained in DC 430AA when it residedin MPC 320B. In such a case, no messages are transmitted to accessterminal 110, in this block 1150. The process then moves to block 1160.

The methodology of the present invention is such that the process doesnot move to block 1170 until it can be assured that the aforementionedpropagation of both low cost routes throughout network 120 has takenplace. The step that is represented by block 1160 is that in which thatassurance is gained. In block 1160, MPC 320B checks whether the secondtimer has expired. In the exemplary embodiment, the first timer willalways have expired at the point at which the second timer has expired.If the second timer has not expired, the process returns to block 1160,where the same check is again performed. In block 1160, if the secondtimer has expired, then the process moves to block 1170. In oneembodiment, block 1140 is not present, and the process moves straightfrom block 1150 to block 1170. In another embodiment, block 1160 checksfor the expiration of the first timer rather than the second timer.

In block 1170, MPC 320B sends a message to its local router, router350B, stating that MPC 320B has the ability to route packets toIP_(DCOAA) and IP_(DCTAA) at a nominally high cost. In the exemplaryembodiment, this message is an OSPF link state advertisement (LSA). Inone embodiment, the message sent is an IP broadcast message, thusallowing a plurality of local routers to receive the message. Therouting cost advertised in this message is nominally high. As all of therouters in network 120 are OSPF capable, this new nominally high costroute, for packets having destination addresses of IP_(DCOAA) andIP_(DCTAA), Will propagate throughout the routers of network 120. Thus,at some point in the future, after the propagation of the routinginformation takes place, the routers will replace the nominally lowcosts associated with routing these packets to MPC 320B with nominallyhigh costs. This step, puts network 120 in a state wherein themethodology of the present invention could once again be used, at alater point in time, to move DC 430AA from MPC 320B to another MPC 320located within network 120. The process then moves to block 1180.

In block 1180, the process of the methodology of the present inventionis complete. One skilled in the art will appreciate that FIGS. 9A-9B areprovides an ordering of the steps for the exemplary embodiment of themethodology of the present invention. One skilled in the art willappreciate that several of the steps can be reordered without departingfrom the scope and spirit of the invention.

The exemplary embodiment of the methodology of the present invention isa novel method for moving an entity containing an IP address from onelocation to another within a network. Not only is this methodology idealfor transparently moving an anchor point within a decentralized servingnetwork of a wireless telecommunications system, but it is also idealfor moving an IP address throughout a corporate or campus network.

The use of OSPF in the exemplary embodiments overcomes some of thedrawbacks that might be encountered in a system that uses Mobile IP.

The first drawback of Mobile IP is that IP packets are susceptible totaking very indirect routes. For instance, take the case where a firstnode moves from its home network to a foreign network, in which a secondnode already resides. In such an instance, if the second node sends oneor more packets to the IP address assigned to the first node, all suchpackets will be routed from the foreign network to the visiting network,and then tunneled back to the foreign network. The use of these indirectroutes introduces latency and causes more bandwidth to be used thanwould have been had a direct route been taken and no extra tunnelingbeen needed.

The second drawback of Mobile IP is the extra overhead that Mobile IPadds to each packet. In Mobile IP, packets routed from a Home Agent to aForeign Agent are encapsulated, thus using extra bandwidth to supportthis overhead.

The third drawback of Mobile IP is its lack of built-in redundancysupport. With Mobile IP, if the Home Agent crashes, a mobile nodevisiting a foreign network will be unable to receive packets, becausethe existing Mobile IP standards do not address the issue of providingHome Agent redundancy.

The present invention provides mobility within a network using a novelmethodology that does not suffer from any of the aforementioneddrawbacks. Thus, the invention can provide great efficiencies innetworks other than those that function as the serving network of awireless telecommunications system. Multiple alternative embodimentsexist that support the use of the methodology of the present inventionin various networks. In one embodiment, an entity containing an IPaddress, such as a laptop computer, frequently sends a broadcast (ormulticast) link state advertisement containing an Age field that isslightly lower than the value of MaxAge. These link state advertisementscontain a cost (metric) equal to a constant value that is nominally low.Thus, when the entity moves from one subnet in the network to another,its old advertisements on the old subnet, containing a nominally lowmetric, quickly reach MaxAge and expire. And, on the new subnet, the newadvertisements with the same nominally low metric quickly take hold,allowing packets to be routed to the new location without the need for atunneling protocol like Mobile IP.

The invention herein uses OSPF as a cost efficient and standardizedmeans for moving an entity throughout a network, which is a novel usewhen compared to the original intention of the OSPF protocol.

In the narrower scope of the present invention, the methodology thatallows for the moving of an anchor point specifically within a wirelesstelecommunications system, alternative embodiments exist. One suchalternative embodiment utilizes Mobile IP to achieve its goal oftransparent mobility of an anchor point within a wirelesstelecommunications system. In such an embodiment, each DC 430 isassociated with a plurality of one or more home agents. In oneembodiment, the OSPF messages described in reference to FIGS. 9A-9Bwould be replaced by Mobile IP registration messages that would be sentby each DC 430 upon its movement from one portion of the system toanother.

FIG. 10A is a network diagram that illustrates the entities that areused in an Internet data connection when access terminal 110 has awireless data communication channel open with a single access point 220Bafter the method of the present invention, described in reference toFIGS. 9A-9B, has been utilized. In particular, FIG. 10A illustrates thenetwork entities that would be in use if access terminal 110 waspreviously connected as diagramed in FIG. 8A, and subsequently themethodology of the present invention, described in reference to FIGS.9A-9B, was utilized. Alternatively, FIG. 10A illustrates the networkentities that would be in use if access terminal 110 was previouslyconnected as diagramed in FIG. 6A, and subsequently a hard-handoff toaccess point 220 was performed, in which the methodology of the presentinvention, described in reference to FIGS. 9A-9B, was utilized.Alternatively, FIG. 10A illustrates the network entities that would bein use if access terminal 110 was previously connected as diagramed inFIG. 7A, and subsequently a hard-handoff to access point 220 wasperformed, in which the methodology of the present invention, describedin reference to FIGS. 9A-9B, was utilized.

In FIG. 10A, all labels have the same meaning as they did in referenceto FIG. 8A, with one exception, as follows. As was explained inreference to FIGS. 9A-9B, DC 430AA physically located within MPC 320B isa copy of the DC 430AA that was physically located within MPC 320A.Although the DCs exist within different MPCs and therefore use adifferent pool of resources, and could there for have been givendifferent labels, the DCs are given the same label of 430AA. This isdone to illustrate that both of the aforementioned DCs have all of thesame attributes, including IP addresses, and perform the same functions,irrespective of their different locations.

FIG. 10B is a diagram showing the exemplary data flow for the Internetdata connection adhering to the data path illustrated in FIG. 10A. Onthe forward link, an IP packet having a destination IP addressassociated with access terminal 110 is travels from Internet 124 overethernet transport 280E to NAS 272. In NAS 272, the packet isencapsulated in a PPP packet, which is further encapsulated into an L2TPpacket with a destination IP address associated with DC 430AA(IP_(DCOAA)), which has been relocated to MPC 320B. This L2TP packet istransmitted over ethernet transport 280D to router 260. Router 260forwards this L2TP packet over Ethernet transport 280C to router 350B.Router 350B then forwards this L2TP packet over Ethernet transport 340Bto its destination of DC 430AA. DC 430AA, located in MPC 320B, receivesthe L2TP packet and unencapsulates the embedded PPP frame. DC 430AA,then, encapsulates the PPP frame into one or more wireless protocolcapsules, which are further encapsulated into IP packets with adestination address associated with MPT 330AA. These IP packets are thentransmitted over ethernet link 34OA to MPT 330AA. MPT 330AAunencapsulates the wireless protocol capsules from the IP packets andtransmits the wireless protocol capsules to access terminal 110 overwireless transport 610.

As is easily understood by one skilled in the art, the opposite path istaken for packets traveling in the direction of the reverse link.

FIG. 11 is a functional block diagram of a preferred embodiment of adecentralized serving network of a wireless telecommunications system.This preferred embodiment is an alternate embodiment to the exemplaryembodiment illustrated in FIG. 2. This preferred embodiment differs fromthe exemplary embodiment as follows.

In FIG. 11, access points 220 communicate with external devices innetwork 120 via transport T1 1120. This contrasts to FIG. 2, in whichaccess point 220 communicates with external devices in network 120 viaethernet 280. It is easily understood by one skilled in the art thattransport T1 1120 is one of a variety of transports, such as E1 ormicrowave, which can be used for connecting access points 220.

In FIG. 11, packets sent from one access point 220A to another accesspoint 220N must first travel through one or more routers 260. This isbecause, as illustrated, each access point is on its own physicalsubnet. This contrasts with FIG. 2, in which packets can be sentdirectly from one access point 220 to another access point 220 over asingle transport. As illustrated in the exemplary embodiment, FIG. 2,this is possible in the exemplary embodiment because transport 280connects to all access points 220. It is easily understood by oneskilled in the art that in a network containing more than one subnet,each subnet need not be restricted to a single access point 220. Inother words, it is easily understood by one skilled in the art that somesubnets can contain exactly one access point 220, while others containmore than one access point 220.

It is also easily understood by one skilled in the art that each accesspoint in a network 120 need not use the same physical transport tocommunicate to other devices in the network. For example, a network 120could be designed such that one access point 220D communicates with arouter 260 via a T1 transport, while another access point 220Ecommunicates with a router 260 via an E1 transport, while another accesspoint 220F communicates with a router 260 via another transport, such asethernet.

Finally, it is easily understood by one skilled in the art that themethodology of the present invention, described herein, works in allsuch embodiments of network 120. In all such embodiments, themethodology of the present invention, described in reference to FIGS.9A-9B, remains the same. This is because the methodology of the presentinvention was designed to be flexible enough such that it would work ina variety of network configurations.

The previous description of the preferred embodiments is provided toenable any person skilled in the art to make or use the presentinvention. The various modifications to these embodiments will bereadily apparent to those skilled in the art, and the generic principlesdefined herein may be applied to other embodiments without the use ofthe inventive faculty. Thus, the present invention is not intended to belimited to the embodiments shown herein but is to be accorded the widestscope consistent with the principles and novel features disclosedherein.

I claim:
 1. In a decentralized serving network of a wirelesstelecommunications system, wherein said decentralized serving networkcomprises a plurality of entities and wherein a first entity of saidplurality of entities contains an anchor point and wherein saiddecentralized serving network also comprises a plurality of routers, andwherein said decentralized serving network also comprises a plurality ofservice devices for providing standardized services for a plurality ofaccess terminals, and wherein said anchor point is in communicationswith a service device of said plurality of service devices, a method forrelocating said anchor point to a second entity of said plurality ofentities, the method comprising the steps: transmitting at least onerelocation message between said first entity and said second entity;copying a set of components of said anchor point from said first entityto said second entity, in accordance with said at least one relocationmessage; and transmitting one or more standard routing messages from oneor more entities of said plurality of entities, wherein said standardrouting messages indicate to one or more routers of said plurality ofrouters that packets containing a destination address associated withsaid anchor point should be routed to said second entity.
 2. The methodof claim 1 wherein: said first entity transmits a first relocationmessage to said second entity; and said first relocation messagecontains component information utilized by said first entity incommunications with said service device.
 3. The method of claim 2wherein said component information contains a first IP (InternetProtocol) address assigned to said anchor point.
 4. The method of claim3, the method further comprising the steps of: said second entityreceiving said first relocation message; said second entity allocatingresources for the creation of a local copy of said anchor point; andsaid second entity initializing said resources in accordance with theinformation contained in said first relocation message.
 5. The method ofclaim 4 wherein said decentralized serving network comprises a firsttransmitting entity, the method further comprising the steps of: formingone or more first standard routing messages that indicate that IPpackets having a destination address of said first IP address should berouted to said second entity; and transmitting, from said firsttransmitting entity, said first standard routing messages to said one ormore routers.
 6. The method of claim 5 wherein said first transmittingentity is said second entity.
 7. The method of claim 5 wherein saidfirst standard routing message is an Open Shortest Path First (OSPF)message containing a cost for said first IP address that is lower thanthe cost of all other currently advertised routes for said first IPaddress.
 8. The method of claim 6 further comprising the step of: saidsecond entity transmitting a second relocation message, based upon theexpiration of a first period of time since said first standard routingmessage was either formed or transmitted.
 9. The method of claim 8further comprising the step of: said second entity transmitting saidsecond relocation message prior to said expiration of said first periodof time, based upon said second entity receiving a packet having adestination IP address of said first IP address prior to said expirationof said first period of time.
 10. The method of claim 9, whereinsubsequent to the transmission of said second relocation message, andwherein said decentralized serving network comprises a secondtransmitting entity, the method further comprising the steps of: formingone or more second standard routing messages that indicate that IPpackets having a destination address of said first IP address associatedwith said anchor point should no longer be routed to said first entity;and transmitting, from said second transmitting entity, said secondstandard routing messages to said one or more routers.
 11. The method ofclaim 10 wherein said second transmitting entity is said first entity.12. The method of claim 10 further comprising the steps of: said firstentity transmitting a third relocation message to said second entity;and said third relocation message contain s said second IP addressassociated with said anchor point.
 13. The method of claim 12, furthercomprising the step of: deallocating the resources of said first entitythat are associated with said anchor point.
 14. The method of claim 12,the method further comprising the steps of: said second entity receivingsaid third relocation message; and said second entity completingconfiguration of said anchor point based upon the contents of said thirdrelocation message.
 15. The method of claim 13, wherein saiddecentralized serving network comprises a third transmitting entity, themethod further comprising the steps of: forming one or more thirdstandard routing messages that indicate that IP packets having adestination address of said second IP address should be routed to saidsecond entity; and transmitting, from said third transmitting entity,said third standard routing messages to said one or more routers. 16.The method of claim 15 wherein said third standard routing message is anOSPF message containing a cost for said second IP address that is lowerthan the cost of all other currently advertised routes for said secondIP address.
 17. The e method of claim 15 further comprising the step of:said second entity transmitting a set of zero or more resynchronizationmessages to an access terminal associated with said anchor point, basedupon the expiration of a second period of time since said third standardrouting message was either formed or transmitted.
 18. The method ofclaim 17 further comprising the step of: said second entity transmittingsaid set of resynchronization messages prior to said expiration of saidsecond period of time, based upon said second entity receiving a packethaving a destination IP address of said second IP prior to saidexpiration of said second period of time.
 19. The method of claim 18,wherein when said first standard routing message or said third standardrouting message is an OSPF message, the method further comprising thesteps: forming one or more fourth standard routing messages thatindicate that although IP packets with destination addresses of saidfirst IP address can still be routed to said second entity, the costassociated with said second entity delivering these packets to adestination of said first IP address will be higher than the cost saidone or more routers currently associate with said second entitydelivering packets to said first IP address; said fourth standardrouting messages are OSPF messages; and transmitting said fourthstandard routing messages to said one or more routers.
 20. The method ofclaim 8 wherein said first standard routing message is a Mobile IPregistration message.
 21. The method of claim 17 wherein said thirdstandard routing message is a Mobile IP registration message.
 22. Themethod of claim 19 wherein said first entity is a first modem poolcontroller and wherein said second entity is a second modem poolcontroller, and wherein said anchor point is a dedicated controller. 23.In a telecommunications system, wherein said telecommunications systemcomprises a service device of a set of at least one service devices, andwherein said telecommunication system comprises a plurality of routers,a method for relocating an anchor point, contained within a first accesspoint, to a second access point during or subsequent to a handoff, andwherein said anchor point is a dedicated controller, comprising thesteps of: transmitting at least one first relocation message from saidfirst access point to said second access point, wherein said firstrelocation message contains dedicated controller component informationassociated with the connection to said at least one service devices;allocating resources for a second dedicated controller at said secondaccess point; initializing said second dedicated controller with saidcomponent information; and transmitting one or more OSPF messages fromsaid second anchor point to one or more of said plurality of routers,wherein said OSPF messages indicate that packets containing adestination IP address associated with said dedicated controller can bedelivered to said dedicated controller by said second access point witha lower cost than they would if said packets were delivered to saidfirst access point.